47Stamp duties of one penny may be denoted by postage stamps and vice versa
On and after the first day of June one thousand eight hundred and eighty-one any stamp duties of one penny which may legally be denoted by adhesive stamps not appropriated by any word or words on the face of them to any particular description of instrument, may be denoted by adhesive penny postage stamps; and on and after that day postage duties may be paid by the use of penny adhesive stamps not appropriated by any word or words on the face of them to postage duty, or to any particular description of instrument.